The proposed training program builds on the successes and lessons of the previous 10 years as it takes a major leap forward. The growing research infrastructure, the growing local expertise, growing NIH funded research opportunities create a new set of challenges and opportunities for this hitherto successful AIDS/TB training program as the program adapts in response to meet the existing and emerging research training needs in South Africa and the region. The past 44 long-term and 69 short-term trainees of the program have been scientifically productive (515 publications including papers in Science, Nature, and Lancet), have made major new scientific contributions, have been instrumental to South Africa's success in securing NIH and other international grants and have taken up several key leadership positions. The continuum of training, research, and mentoring between the US and SA in the previous cycle has already gone some way towards equalizing the partnership between the US and South African but more still needs to be done, especially as the challenge of training for treatment provision and treatment program evaluations becomes more immediate. The emphasis of the program in this current cycle will be to identify critical gaps in existing centers of research excellence in South Africa and recruit, train and mentor appropriate enthusiastic, bright young and established mid-level investigators to provide them with the knowledge base and skills needed for the design and conduct of large-scale clinical trials (esp for vaccines and microbicides); pathogenesis studies, studies on the HIV/TB interaction and evaluation of the impact of ARV treatment. The goal is to strengthen existing and expand the number of independent HIV-related research teams in South Africa; strengthen South Africa's capacity to assume more of the country's and region's training needs and developing the skills needed to operationalize, implement and monitor the South African scale-up of AIDS treatment. Guided by the ongoing assessment of training priorities and with careful oversight from a balanced US-SA Scientific Advisory Committee, we will continue to provide as appropriate a variety of short-to-medium, and long-term training opportunities in the US and South Africa. Priority will be given to trainees from recognized AIDS research groups. Vigorous effort will go towards equalization of the training opportunities between the US and South Africa. This includes the establishment of a high quality masters program in epidemiology in South Africa taught initially jointly by US and South African faculty. A rich tapestry of AIDS and TB projects funded by NIH, CDC, and others offer diverse training and research opportunities to trainees for their placements. Overall, this program is designed to increase the number of independent established AIDS and TB researchers in South Africa so that there is local critical mass for future in-country mentorship and training. While this is a long-term goal, the proposed program sets about this task well armed with the most valuable lessons learnt in the last 5 years such as the importance of ongoing in-country mentorship, guidance and support, assistance with grant writing, and recruitment of candidates who are already in productive research groups.